Trimodality therapy for locally advanced esophageal squamous cell carcinoma: the role of volume-based PET/CT in patient management and prognostication

The prognostic value of pretreatment [18F]FDG PET/CT parameters in esophageal cancer: a meta-analysis

OBJECTIVES

This study aims to evaluate the prognostic implications of pretreatment [18F]FDG-PET metrics in esophageal cancer patients through a meta-analysis of the existing literature.

METHODS

We carefully searched electronic databases, including PubMed and Embase, from inception to April 1, 2024, to identify studies describing the prognostic value of pretreatment PET metrics for advanced esophageal cancer. Clinical endpoints examined were overall survival (OS), recurrence-free survival (RFS)/disease-free survival (DFS), and progression-free survival (PFS). Hazard ratios (HRs) for PFS and OS were taken directly from the original reports.

RESULTS

Forty-seven publications, including 5504 patients, were included in our analysis. OS and PFS were analyzed in 31 and nine studies, respectively, and DFS/RFS was analyzed in 16 studies. The comprehensive pooled analysis revealed significant associations between metabolic parameters derived from positron emission tomography (PET) imaging and clinical outcomes. Expressly, the pooled HR indicated that patients with higher SUVmax were significantly associated with poor PFS (HR: 1.06; 95% CI: 1.01-1.12, p = 0.011) and poor RFS/DFS (HR: 1.09; 95% CI: 1.02-1.18, p = 0.019). Patients with higher SUVmean were significantly associated with poorer OS (HR: 1.07; 95% CI: 1.01-1.14, p = 0.025). High MTV was significantly associated with inferior OS (HR: 1.02; 95% CI: 1.00-1.05, p = 0.049). High TLG was significantly associated with poorer RFS/DFS (HR: 2.02; 95% CI: 1.11-3.68, p = 0.022).

CONCLUSION

This study unveiled pretreatment FDG-derived parameters as valuable prognostic indicators in assessing esophageal cancer outcomes. Specifically, SUVmax is associated with PFS and RFS/DFS. SUVmean and MTV were correlated with OS, and TLG was only associated with RFS/DFS.

KEY POINTS

Question Inconsistent findings on the prognostic value of pretreatment [18F]FDG PET parameters in esophageal cancer require comprehensive analysis to clarify their role in outcome prediction. Findings Higher pretreatment [18F]FDG-PET metrics (SUVmax, SUVmean, MTV, TLG) are associated with poor survival outcomes, emphasizing their potential value in enhancing prognostic assessments for esophageal cancer. Clinical relevance This study highlights the prognostic significance of pretreatment [18F]FDG-PET metrics in esophageal cancer, providing valuable insights for patient outcome prediction and potentially guiding personalized treatment strategies.

Prognostic significance of PET/CT and its association with immuno-genomic profiling in oesophageal squamous cell carcinoma treated with immunotherapy plus chemoradiotherapy: results from a phase II study

BACKGROUND

A phase II trial (EC-CRT-001) demonstrated the promising efficacy of combining toripalimab (an anti-PD-1 antibody) with definitive chemoradiotherapy (CRT) for locally advanced oesophageal squamous cell carcinoma (ESCC). Biomarkers are key to identifying patients who may benefit from this therapeutic approach.

METHODS

Of the 42 patients with ESCC who received toripalimab combined with definitive CRT, 37 were included in this analysis. Baseline assessments included PET/CT metabolic parameters (SUVmax, SUVmean, SUVpeak, MTV, and TLG), RNA sequencing of tumour biopsies to quantify the tissue mutational burden (TMB), and multiplex immunofluorescence staining to estimate immune cell infiltration in the tumour microenvironment (TME). Frozen neoplastic samples were procured for RNA sequencing to further explore the immune-related TME.

RESULTS

Among the 37 patients, high baseline SUVmax (≥12.0; OR = 6.5, 95% CI 1.4-48.2, p = 0.032) and TLG (≥121.8; OR = 6.8, 95% CI 1.6-33.5, p = 0.012) were significantly correlated with lower complete response rates. All five PET/CT parameters were notably associated with overall survival; only SUVmax and TLG were associated with a significantly worse progression-free survival. A trend towards an inverse correlation was observed between SUVmax and TMB (R = -0.33, p = 0.062). PD-1 + CD8 + T cell infiltration was negatively correlated with MTV (R = -0.355, p = 0.034) and TLG (R = -0.385, p = 0.021). Moreover, RNA sequencing revealed that the high TLG subgroup exhibited low immune cell infiltration, indicating an immunosuppressive landscape.

CONCLUSIONS

High baseline SUVmax and TLG might predict poorer treatment response and worse survival in patients with ESCC undergoing immunotherapy combined with CRT. In addition, high PET/CT metabolic parameters, particularly TLG, were correlated with an immunosuppressive TME, which warrants further exploration.

PET/CT deep learning prognosis for treatment decision support in esophageal squamous cell carcinoma

OBJECTIVES

The clinical decision-making regarding choosing surgery alone (SA) or surgery followed by postoperative adjuvant chemotherapy (SPOCT) in esophageal squamous cell carcinoma (ESCC) remains controversial. We aim to propose a pre-therapy PET/CT image-based deep learning approach to improve the survival benefit and clinical management of ESCC patients.

METHODS

This retrospective multicenter study included 837 ESCC patients from three institutions. Prognostic biomarkers integrating six networks were developed to build an ESCC prognosis (ESCCPro) model and predict the survival probability of ESCC patients treated with SA and SPOCT. Patients who did not undergo surgical resection were in a control group. Overall survival (OS) was the primary end-point event. The expected improvement in survival prognosis with the application of ESCCPro to assign treatment protocols was estimated by comparing the survival of patients in each subgroup. Seven clinicians with varying experience evaluated how ESCCPro performed in assisting clinical decision-making.

RESULTS

In this retrospective multicenter study, patients receiving SA had a median OS 9.2 months longer than controls. No significant differences in survival were found between SA patients with predicted poor outcomes and the controls (p > 0.05). It was estimated that if ESCCPro was used to determine SA and SPOCT eligibility, the median OS in the ESCCPro-recommended SA group and SPOCT group would have been 15.3 months and 24.9 months longer, respectively. In addition, ESCCPro also significantly improved prognosis accuracy, certainty, and the efficiency of clinical experts.

CONCLUSION

ESCCPro assistance improved the survival benefit of ESCC patients and the clinical decision-making among the two treatment approaches.

CRITICAL RELEVANCE STATEMENT

The ESCCPro model for treatment decision-making is promising to improve overall survival in ESCC patients undergoing surgical resection and patients undergoing surgery followed by postoperative adjuvant chemotherapy.

KEY POINTS

ESCC is associated with a poor prognosis and unclear ideal treatments. ESCCPro predicts the survival of patients with ESCC and the expected benefit from SA. ESCCPro improves clinicians' stratification of patients' prognoses.

Pathological response to neoadjuvant chemoradiotherapy for oesophageal squamous cell carcinoma in Eastern versus Western countries: meta-analysis

OBJECTIVE

Locally advanced oesophageal squamous cell carcinoma can be treated with neoadjuvant chemoradiotherapy or chemotherapy followed by oesophagectomy. Discrepancies in pathological response rates have been reported between studies from Eastern versus Western countries. The aim of this study was to compare the pathological response to neoadjuvant chemoradiotherapy in Eastern versus Western countries.

METHODS

Databases were searched until November 2022 for studies reporting pCR rates after neoadjuvant chemoradiotherapy for oesophageal squamous cell carcinoma. Multi-level meta-analyses were performed to pool pCR rates separately for cohorts from studies performed in centres in the Sinosphere (East) or in Europe and the Anglosphere (West).

RESULTS

For neoadjuvant chemoradiotherapy, 51 Eastern cohorts (5636 patients) and 20 Western cohorts (3039 patients) were included. Studies from Eastern countries included more men, younger patients, more proximal tumours, and more cT4 and cN+ disease. Patients in the West were more often treated with high-dose radiotherapy, whereas patients in the East were more often treated with a platinum + fluoropyrimidine regimen. The pooled pCR rate after neoadjuvant chemoradiotherapy was 31.7% (95% c.i. 29.5% to 34.1%) in Eastern cohorts versus 40.4% (95% c.i. 35.0% to 45.9%) in Western cohorts (fixed-effect P = 0.003). For cohorts with similar cTNM stages, pooled pCR rates for the East and the West were 32.5% and 41.9% respectively (fixed-effect P = 0.003).

CONCLUSION

The pathological response to neoadjuvant chemoradiotherapy is less favourable in patients treated in Eastern countries compared with Western countries. Despite efforts to investigate accounting factors, the discrepancy in pCR rate cannot be entirely explained by differences in patient, tumour, or treatment characteristics.

Potential Predictive Immune and Metabolic Biomarkers of Tumor Microenvironment Regarding Pathological and Clinical Response in Esophageal Cancer After Neoadjuvant Chemoradiotherapy: A Systematic Review

INTRODUCTION

The tumor microenvironment (TME) plays a crucial role in therapy response and modulation of immunologic surveillance. Adjuvant immunotherapy has recently been introduced in post-surgery treatment of locally advanced esophageal cancer (EC) with residual pathological disease after neoadjuvant chemoradiotherapy (nCRT). F-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) remains a valuable imaging tool to assess therapy response and to visualize metabolic TME; however, there is still a paucity in understanding the interaction between the TME and nCRT response. This systematic review investigated the potential of TME biomarkers and 18F-FDG-PET/CT features to predict pathological and clinical response (CR) after nCRT in EC.

METHODS

A literature search of the Medline and Embase electronic databases identified 4190 studies. Studies regarding immune and metabolic TME biomarkers and 18F-FDG-PET/CT features were included for predicting pathological response (PR) and/or CR after nCRT. Separate analyses were performed for 18F-FDG-PET/CT markers and these TME biomarkers.

RESULTS

The final analysis included 21 studies-10 about immune and metabolic markers alone and 11 with additional 18F-FDG-PET/CT features. High CD8 infiltration before and after nCRT, and CD3 and CD4 infiltration after nCRT, generally correlated with better PR. A high expression of tumoral or stromal programmed death-ligand 1 (PD-L1) after nCRT was generally associated with poor PR. Moreover, total lesion glycolysis (TLG) and metabolic tumor volume (MTV) of the primary tumor were potentially predictive for clinical and PR.

CONCLUSION

CD8, CD4, CD3, and PD-L1 are promising immune markers in predicting PR, whereas TLG and MTV are potential 18F-FDG-PET/CT features to predict clinical and PR after nCRT in EC.

The role of 18F-FDG PET/CT in predicting the pathological response to neoadjuvant PD-1 blockade in combination with chemotherapy for resectable esophageal squamous cell carcinoma

PURPOSE

Accurate assessment of residual disease of tumor and lymph nodes after neoadjuvant immunochemotherapy is crucial in the active surveillance for patients with pathological complete response (pCR) and the optimal extent of lymphadenectomy for patients with non-pCR. This post hoc analysis aimed to evaluate the performance of ¹⁸F-FDG PET/CT to predict the pathological response to neoadjuvant immunochemotherapy for esophageal squamous cell carcinoma (ESCC).

METHODS

Fifty-eight resectable ESCC patients received two cycles of camrelizumab in combination with chemotherapy and were enrolled in the final analysis. The ¹⁸F-FDG PET/CT scans were acquired at baseline (scan-1) and after immunochemotherapy but prior to surgery (scan-2). Maximum standardized uptake value (SUV_max), mean standardized uptake value (SUV_mean), tumor-to-blood pool SUV_max ratio (SUV_TBR), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were evaluated for their association with the pathological response to immunochemotherapy.

RESULTS

Nineteen patients (32.8%, 19/58) had pCR and thirty-nine patients (67.2%, 39/58) had non-pCR after two doses of camrelizumab and chemotherapy. At scan-2, the SUV_max, SUV_mean, SUV_TBR, TLG, and MTV were significantly lower in pCR than in non-pCR patients. Decrease in TLG and MTV between scan-2 and scan-1 of the same patient was significantly higher in the pCR than in the non-pCR group. In the receiver operating characteristic curve analysis, SUV_max, SUV_mean, SUV_TBR, TLG, and MTV in scan-2 showed excellent predictive value for the pCR of primary tumors. Furthermore, SUV_max in scan-2 were higher in positive lymph nodes than in negative ones, suggesting a high negative predictive ability (98.6%) with a cut-off value at 1.4.

CONCLUSION

The parameters of ¹⁸F-FDG PET/CT have the excellent performance for predicting pCR after the combined neoadjuvant immunochemotherapy in resectable ESCC.

TRIAL REGISTRATION

ChiCTR2000028900. Registered on January 6, 2020.

18F-FDG-PET/CT-measured parameters as potential predictors of residual disease after neoadjuvant chemoradiotherapy in patients with esophageal carcinoma

Objective

To evaluate the maximum and mean standardized uptake values, together with the metabolic tumor value and the total lesion glycolysis, at the primary tumor site, as determined by ¹⁸F-fluorodeoxyglucose positron-emission tomography/computed tomography (¹⁸F-FDG-PET/CT), performed before and after neoadjuvant chemoradiotherapy (nCRT), as predictors of residual disease (RD) in patients with esophageal cancer.

Materials and Methods

The standardized uptake values and the volumetric parameters (metabolic tumor value and total lesion glycolysis) were determined by ¹⁸F-FDG-PET/CT to identify RD in 39 patients before and after nCRT for esophageal carcinoma. We used receiver operating characteristic curves to analyze the diagnostic performance of ¹⁸F-FDG-PET/CT parameters in the definition of RD. The standard of reference was histopathological analysis of the surgical specimen.

Results

Eighteen patients (46%) presented RD after nCRT. Statistically significant areas under the curve (approximately 0.72) for predicting RD were obtained for all four of the variables evaluated after nCRT. Considering the presence of visually detectable uptake (higher than the background level) at the primary tumor site after nCRT as a positive result, we achieved a sensitivity of 94% and a specificity of 48% for the detection of RD.

Conclusion

The use of ¹⁸F-FDG-PET/CT can facilitate the detection of RD after nCRT in patients with esophageal cancer.